3 underwhelming games were released with the same relative features & new inaccurate car models with terrible visuals, and a bad simulation with permanent assists on. Which is why no one bought forza, and no ability to use your wheel from your PC/PS3 with the game.
PD also released prologues, kept them updated, and a psp game with the basic content in sub-hd. 4 releases for animated air brakes and spoilers, I'd imagine in 7 years they might be able to add correct car models and a new brush for the livery editor, or a real life loop so you can drive your car upside down.
Its clear as day that the polish in GT is because they could dedicate the time to it & had a vision, and the audience would allow for it. It took 4 games for turn10 to realize what Top Gear was. We are talking about a car sim here, really not a whole lot of content to be had, lets be honest. These things were all in Kaz's "When we can actually do it well, we will do it". mantra, its not PD coming up with these ideas, its just them coming up with what makes a driving sim.
Turn10 has had ample time to add what was in GT5 from FM1+, all they did was create a yeah-me-too game, that failed to hit the mark. Its hard to give them props, when they could have lead the game with weather/track creator/top gear/etc. Instead, they update the livery editor, and a tire model thats rendered useless when its countered by permanent assists. Or unrealistic drivetrain swaps, that are literally impossible to calculate...
Gt5's problems are its dated car roster, which is utterly pathetic, and track list. But the creator makes up for that for people like me, who are just plain addicted to driving.